Differences in the heritability of craniofacial skeletal and dental characteristics between twin pairs with skeletal Class I and II malocclusions

• Published in: Korean journal of orthodontics (2012) Vol. 51; no. 6; pp. 407 - 418
• Main Authors: Park, Heon-Mook, Kim, Pil-Jong, Sung, Joohon, Song, Yun-Mi, Kim, Hong-Gee, Kim, Young Ho, Baek, Seung-Hak
• Format: Journal Article
• Language: English
• Published: Korea (South) 대한치과교정학회 25.11.2021; Korean Association of Orthodontists
• Subjects: Original; 치의학; Heritability; Twins; ACE model; Principal component analysis
• ISSN: 2234-7518; 2005-372X
• DOI: 10.4041/kjod.2021.51.6.407

To investigate differences in the heritability of skeletodental characteristics between twin pairs with skeletal Class I and Class II malocclusions. Forty Korean adult twin pairs were divided into Class I (C-I) group (0° ≤ angle between point A, nasion, and point B [ANB]) ≤ 4°; mean age, 40.7 years) and Class II (C-II) group (ANB > 4°; mean age, 43.0 years). Each group comprised 14 monozygotic and 6 dizygotic twin pairs. Thirty-three cephalometric variables were measured using lateral cephalograms and were categorized as the anteroposterior, vertical, dental, mandible, and cranial base characteristics. The ACE model was used to calculate heritability (A > 0.7, high heritability). Thereafter, principal component analysis (PCA) was performed. Twin pairs in C-I group exhibited high heritability values in the facial anteroposterior characteristics, inclination of the maxillary and mandibular incisors, mandibular body length, and cranial base angles. Twin pairs in C-II group showed high heritability values in vertical facial height, ramus height, effective mandibular length, and cranial base length. PCA extracted eight components with 88.3% in the C-I group and seven components with 91.0% cumulative explanation in the C-II group. Differences in the heritability of skeletodental characteristics between twin pairs with skeletal Class I and II malocclusions might provide valuable information for growth prediction and treatment planning.